E46 Rear Subframe Removal Guide

Rear Subframe Removal and Installation Instructions for E46 chassis

• Part name: E46 BMW Rear Chassis Reinforcement Plates
• Part number: K0117
• Product page: https://www.garagistic.com/products/e46-bmw-rear-chassis-reinforcement-plates?_pos=3&_psq=e46-rein&_ss=e&_v=1.0
• Difficulty level: 10

The following steps can be found below:  Raising The Vehicle, Exhaust Removal,  Brake Caliper Removal,  Removing Rear Suspension, Disconnecting Driveshaft, Disconnecting Trailing Arms, Handbrake Cables, Removing Subframe

This article will cover the main points on removing an E46 rear subframe. This is a common practice for any E46 owner. Whether it be to replace worn out bushings, reinforce the subframe mounting points on the chassis, or repair cracks or tears in the unibody caused by years of hard-driving. Removing an E46 rear subframe isn't hard, but it can be time-consuming. This article will cover removing the entire subframe as a whole. This is the most effective method as it requires the least amount of work. It also benefits those doing it on jack stands as a simple floor jack can be used to remove the entire subframe and slide it out from under the car.

Raising The Vehicle

Required Tools

• Two Floor Jacks (one is acceptable)
• Four Jack Stands
• Mechanics Gloves
• 1/2" Electric Impact (Ratchet and Socket are fine)

Procedure

Step 1: Jack the rear of the vehicle up as high as you can. To do this you'll want to put the jack under the rear subframe on the section that wraps around the diff.

Step 2: Place jack stands under the rear side lift pads. Be sure to get them as high as possible while still being sturdy.

Step 3: Lower vehicle on to lift pads. Make sure the vehicle is secure and not rocking on uneven stands.

Step 4: Using both jacks at both front lift pads, evenly raise the vehicle until it is level with the rear jack stands

Step 5: Place the second set of jack stands under center frame rails at the front of the vehicle.

Step 6: Lower vehicle on to jack stands. Make sure the vehicle is secure and not rocking on uneven jack stands.

Step 7: Using 1/2" impact and socket remove rear wheels and place to the side.

Exhaust Removal

Required Tools

• 1/2" Impact
• 13mm Socket
• 17mm Socket
• 17mm Wrench
• Ratchet
• Extension

Procedure

Step 1: Remove eight 13mm bolts from the front skid plate using 1/2" impact and remove the skid plate from the vehicle.

Step 2: Using 1/2" impact, 17mm socket, and 17mm wrench unbolt the four bolts connecting the exhaust to the headers.

Step 3: Move to the rear of the vehicle and use a 13mm socket, extension, and impact to remove the four bolts on the rubber exhaust hangers and let the entire exhaust droop. 

Step 4: Move to the center of the vehicle and remove the eight 13mm bolts holding the center of the exhaust section, and carefully lower the entire exhaust system down.

Step 5: Slide exhaust out from under the vehicle and place somewhere out of the way.

Brake Caliper Removal

Required Tools

• 2 Long Flat Screwdrivers
• 3/8" Ratchet
• 7mm Allen Socket
• Zip ties or strong wire

Procedure

Step 1: Using a screwdriver remove the plastic cap from caliper dust covers

Step 2: Using one screwdriver, use one to apply pressure on the inside of the caliper anti-rattle clip and press out. Use second screwdriver to pry anti-rattle clip out of the caliper. 

Step 3: Using one screwdriver, insert it into caliper through to brake pad and pry brake pad back compressing caliper.

Step 4: Using the 7mm socket and 3/8" ratchet unbolt caliper from caliper bracket and remove caliper guide pins from the caliper.

Step 5: Slide calipers off of rotor and caliper bracket.

Step 6: Using zip ties or wire hang caliper bracket in a safe location away from the subframe

Removing Rear Suspension

Required Tools

• 1/2" Impact
• 18mm socket
• Jack

Step 1: Ensure the handbrake is disengaged.

Step 2: Place a jack under rear shock and raise jack to meet rear shock.

Step 3: Using 18mm socket and impact unbolt shock

Step 4: Slowly lower the jack until the rear spring can be removed.

Step 5 (Optional): In trunk go to rear shock towers and unbolt two 13mm nuts holding rear shocks.

Disconnecting Driveshaft

Required Tools

• 17mm Socket or E12 E-Torx Socket
• 10mm Socket
• 13mm Socket
• Extension
• 3/8" Ratchet
• 1/2" Impact
• Small/Medium Pry Bar

Step 1: Using an impact and a 10mm socket unbolt the heat shield covering the front subframe brace.

Step 2: Using Impact, 13mm, and 18mm socket unbolt front subframe brace. There will be two 18mm bolts and 4 13mm bolts.

Step 3: Take the E12 or 17mm socket and extension and unbolt the driveshaft from the input shaft on the differential. This will either be a six-bolt E12 or four-bolt 17mm.

Step 4: Using the pry bar insert it into the recess found on the outside edge of the driveshaft where it goes into the input shaft and pry the two flanges apart.

Step 5: Move the driveshaft out of the way so that it does not contact the subframe when removing.

Disconnecting Trailing Arms

Required Tools

• Jack
• 18mm Socket
• 1/2" Impact
• Extension

Step 1: Place a jack under the middle of trailing arm and support trailing arm from underneath.

Step 2: Use your impact or wrench, extension, and 18mm socket to unbolt the trailing arms from the body. There are three bolts per side.

Step 3: Lower the trailing arm and allow it to rest disconnected from the body.

Handbrake Cables

Required Tools

• Pocket Screwdriver or trim removal tool
• 10mm Socket
• 3/8 Ratchet
• Extension
• 10mm wrench

Step 1: Inside vehicle remover parking brake leather cover using pocket screwdriver or trim removal tool.

Step 2: Using a ratchet, extension, 10mm socket, and 10mm wrench unbolt the parking brake cables from the parking brake handle.

Step 3: Push parking brake cables into the parking brake cable tube as far as allowable. This will make lowering the subframe easier

Removing Subframe

Required Tools

• Two Floor Jacks
• 1/2" Impact
• 18mm Socket

Step 1: Use a floor jack to support the subframe at the front brace that surrounds the diff snout. 

Step 2: Use a second jack to support the subframe from the rear section of diff. This will equalize pressure on the subframe mounts so the subframe doesn't bind up on the studs in the chassis.  

Step 3: Using impact and 18mm socket unbolt the rear subframe nuts

Step 4: Carefully lower both jacks at the same speed and the subframe should drop with little to no effort. If the subframe hangs. Raise jacks back up and use a pry bar to help move the subframe down the studs.

*Be sure to lower the front and rear of the subframe in increments and carefully pull the parking brake cables out with the subframe.